Apparatus for heating metal electrically



(No Model.) 2 Sheets-Sheet 1.

0. L. GOFFIN. APPARATUS FOR HEATING METALS ELEOTRIUALLY. No. 520,299.Patented May 22, 1894.

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(No Model.) 2 Sheets-Sheet 2. 0. OOPFIN. APPARATUS FOR HEATING METALSELEGTRIGALLY. No. 520,299.

Patented May 22, 1894.

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STATES PATENT OFFICE.

CHARLES L. COFFIN, OF DETROIT, MICHIGAN.

APPARATUS FOR HEATING METAL ELECTRICALLY.

sFECIFIGATION forming part of Letters Patent No. 520,299, dated May 22,1894.

Application filedOctober 5 1893. Serial No. 487,242. (No model- To allwhom it may concern:

Be it known that 1, CHARLES L. 00mm, of Detroit, in the county of Wayneand State of Michigan, have invented a new and useful Improvement inApparatus for Heating Metals Electrically, of which the following is aspecification.

My invention consists in an improvement in method of and apparatus forheating metal electrically, hereinafter fully described and claimed. Inthe accompanying drawingsFigure 1 1s a sectional elevation of myimproved apparatus. Fig. 2 is a detail sectional view, show- 1ng one endportion of the conductor 00. Fig. 3 is a detail vertical sectional viewthrough the conductor D and one of the electrodes; and Fig. 4 is anelevation of the apparatus ad usted to produce the voltaic arc.

A represents a table suitably supported and insulated.

J represents a goose neck or standard secured on and rising from tableA, and carrying on its end a collar K.

N represents a rod which passes through collar K. For raisingand-lowering rod N, it may be screw threaded and engage with a nut Mwhich rides on collar K and is kept in place by lugs L.

Irepresen'ts a block of insulating material carried on rod N in which issecured a metal rod E, and a series of insulated electrodes 0,preferably of carbon, each electrode 0 being provided with a contactplate of metal G.

D represents a conductor adapted tomove in electrical contact with rodE, and carries a brush F making contact with plate G on electrode 0.

:1: represents a conductor preferably terminating in a collar H, bywhich rod E is con nected with one terminal of a generator ofelectricity. B represents the material to be heated, connected byconductor y with the other terminal of the generator.

The operation of myinvention is as follows: Material B being placed inposition and connected with the generator, electrodes 0 are brought incontact with B, thus establishing a circuit through conductor 00, rod E,conductor D,brush F, contact plate G, one electrode 0, material B andconductor y. When this electrode 0 becomes hot, brush F is shifted tothe contact plate G of the next electrode 0,

and when this second electrode becomes hot, brushF is shifted to thenext electrode Q. As

electrodes 0 heat very readily and retain their I heat a considerabletime, quite a number of them can be heated, and then by shifting brush Fmore rapidly they are all maintained at a high heat, and heat material13 by incandescence. In this manner quite a long seam or joint can bebrought to welding heat with but little expenditure of power, since thecurrent need be only sufficient to heat one electrode 0 to the desiredtemperature. This process is especially useful in heating sheet metalfor welding, in cases where the arc process develops too much heat andwhere it is very difficult to bring the edges to be Welded into contactand pass a heating current across the joint.

.I have illustrated the electrodes 0 as arranged in a straight line, forheating a straight seam, but it isevident that they may be arranged inany curve, or in a circle.

The apparatus in Fig. 1 is intended for use by direct contact with thematerial, but by first bringing the electrode in contact with thematerial, and then raising it slowly from the material, to the positionshown in Fig. 4, the current being passing, a voltaic arc will beproduced, which are may be moved backward and forward by moving thecontact piece.

I do not herein claim the method of heating metal by subjecting the sameto the influence of a moving voltaic arc while simultaneously heated byradiation from incandescent electrodes in proximity to,but not incontact with the metal, as such constitutes the subject-matter of myapplication for Letters Patent filed October 7, 1893, Serial No.487,453.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. In an apparatus for heating metal electrically, the combination of aplurality of high resistance electrodes, metallic conducting clampssustaining said electrodes, and means for insulating said electrodes andclamps from each other, a movable contact device connected to oneterminal of a source of electric energy, and adapted to make contactwith said conducting clamps, severally and successively bringing saidhigh resistance electrodes into circuit with the metal, and means forconnecting the same to the other terminal of the source of electricenergy.

2. In an apparatus for heating metal electrically, the combination witha plurality of high resistance electrodes insulated from the metal,means for connecting said metal to the terminal of a source of electricenergy, sup.- port for the electrodes, means for raising and loweringsaid electrodes, a movable contact device, and means for connecting saidcontact device to the other terminal of the source of energy. 7

3. In an apparatus for electrically heating metal, the combination with'the metal and means for connecting said metal to one terminal of asource of electric energy, of a plurality of high resistance electrodesinsulated 5 from each other, a movable adjustable support for saidelectrodes, a movable contactdej vice connected to the other terminal ofthe source of energy, and means for bringing said electrodes severallyand successively into the which said electrodes may be successivelyelectric circuit.

4.. In an apparatus for heating metal electrio-ally, the combinationwith a support for the metal to be heated and means for con- 1 meetingsaid metal with one terminal of a generator, of a series of highresistance electrodes insulated from each other, means for bringing saidelectrodes in contact with the metal, and means for connecting saidelectrodes severally and successively with the other terminalofthe'generator, substantially as shown and described.

5. In an apparatus for electrically heating metal by means of anelectric arc, the com- 'bination'of a plurality of electrodes, a contactdevice by means of which said electrodes may be successively thrown incircuit, means for moving said contact device, and means for maintainingan electric arc between the metal and the electrodes successively thrownin circuit.

6. In an apparatus for electrically heating by means of the electricarc, the combination of a plurality of electrodes insulated from eachother, a contact device by means of which said electrodes may besuccessively thrown in circuit, means for moving said contact devicewith means for maintaining an electric are between said electrodessuccessively thrown in circuit. 7

7. In an apparatus for electrically heating by means of the electricarc, the combination of a plurality of electrodes insulated from eachother, a contact device by means of which said electrodes may besuccessively thrown in circuit, means for moving said contact device,and means for maintaining an electric are between another electrode andthe 'first named electrodes as successively thrown in circuit.

8. In an apparatus for electrically heating by means of the electricarc, the combination of an electrode connected to one terminal of asource of electric energy, with a plurality of electrodes insulated fromeach other,acontact device connected to the other terminal of the sourceof electric energy, by means of thrown in circuit, means for movingsaidcontact device, and means for maintaining an electric are betweensaid first named electrode and the said insulated electrodes assuccessively thrown in circuit.

9. In an apparatus for electrically heating by means of the electricarc, the combination of an electrode connected to one terminal of asource of electric energy, a movable conductor connected to the otherterminal of said source of electric energy, a series of insulatedconductors adapted to be successively placed in circuit by said movableconductor, and means for maintaining an electric are between said firstnamed electrode and the insulated electrodes, as successively thrown incircuit.

CHARLES L. COF'FIN.

Witnesses:

AMELIA WILLIAMS, DENTON GUINNESS.

